There is a beautiful specimen growing at Plant Delights Nursery near Raleigh, NC. They have pruned it to a single trunk, making it more of a small tree with beautiful, weeping form. It is planted on a slight rise, with a path below, so when you walk under it the flowers are just above or at your height. The perfect use of this beautiful plant, in my opinion!

I have two, in the ground for two years in an area that does not get as much sun as they might desire. Mine have not shown any signs of spreading, though they are good sized plants. Perhaps lack of light or competition from other plants slows the urge to sucker.

I agree with the opinion stated above that they appear to be more mite resistant. Mine are planted side by side with the more common buddleia, which are infested almost every year with spider mites. These don't become infested.

It has such a graceful weeping habit, and dark green leaves. The foliage is quite dense and compact, not leggy and floppy like the davidii.

The blooms just go, & go& go...
They continue down the raceme, blooming as they grow longer. This is a butterfly magnet, as well as hummingbird and bumble bee attractor. This bush is in full bloom even in the very hottest part of our scorching TX summers(over 100 degrees).

Not many people know about this one, but I highly recommend it!

I've not experienced the suckering, and I've had mine for many years, now. I guess if it did start to sucker, I'd be happy to dig them, so I could share this wonderful bush.

This Buddleja looks nothing like the typical Buddleja. Its foliage is a lustrous dark green and appears more mite resistant than the B. davidii cultivars. Flowers are formed on new growth so pruning to remove spent flowers results in more flowers. The flowers are non-fragrant, however butterflies are as prevalent on this species as they are on B. davidii.

Although I'd like to give this a Positive rating because of its lovely foliage and flowers, I'm giving it a Neutral because it has proven almost weedy in our gardens with runners showing up throughout the garden as much as 10 feet from the base of the plant and has become a nuisance to control.
Extremely easy to root from cuttings.

Yes, this species can start to spread via underground stems - not a hideous pest, but you will find it showing up here and there in a small garden. Good for more of a 'hedgerow' planting where it can be appreciated and its suckering is not a problem. I love the 'up-side-down' flower spikes which arch out and down - appealing to be surprised by one while walking on a path. They also make fabulous cut flowers, lasting a very long time, opening more flowers over time towards the spike tip. On the plant individual spikes can actually continue to expand and open flowers continuously, becoming 12, 24, or 36 inches long!!! Many spikes will resprout from the same stem, but eventually this stem will exhast itself and should be cut out at the base of the plant.

A relatively unknown, this species is frequently overlooked in favor of the numerous cultivars of Buddleia davidii, this Chinese native has a lot going for it - smooth foliage, pendulous flowers grace a weeping form and cinnamon-colored stems that don't require the same hard pruning as other Butterfly Bushes. IMO, it deserves a home in more gardens :)